Preparation of modified wood

A method for preparing modified wood comprising treating wood with an aqueous water repellent [I] and treating the same with an emulsion water repellent [II],

• said aqueous water repellent [I] comprising a product obtained through co-hydrolytic condensation of
• (A) 100 parts by weight of an organosilicon compound of the general formula (1):
• (R1)a(OR2)bSiO(4−a−b)/2 (1)
• wherein R1 is a C1-6 alkyl group, R2 is a C1-4 alkyl group, a is a positive number of 0.75 to 1.5, b is a positive number of 0.2 to 3, satisfying 0.9<a+b≦4, and
• (B) 0.5 to 49 parts by weight of an amino-containing alkoxysilane of the general formula (2):
• R3R4NR5—SiR6n(OR2)3-n (2)
• wherein R2 is as defined above, R3 and R4 are each independently hydrogen or a C1-15 alkyl or aminoalkyl group, R5 is a divalent C1-18 hydrocarbon group, R6 is a C1-4 alkyl group, and n is 0 or 1, or a partial hydrolyzate thereof, in the presence of an organic or inorganic acid,
• said emulsion water repellent [II] being a trialkylsiloxysilicate emulsion water repellent obtained by polymerizing
• (C) an organodisiloxane of the general formula (3):
• R73Si—O—SiR73 (3)
• wherein R7 is each independently a C1-10 alkyl group, and
• (D) at least one of a tetraalkoxysilane of the general formula (4):
• Si(OR7)4 (4)
• wherein R7 is each independently a C1-10 alkyl group, and a partial hydrolytic condensate thereof,
• in such a proportion that the molar ratio of trialkylsiloxy units:
• R73SiO0.5 in component (C) to tetrafunctional units:
• SiO4/2 in component (D) may fall in a range of 0.5 to 2.0, in an aqueous solution containing (E) a surfactant and (F) water at a temperature of 30 to 90° C.